Gyro-controlled servomotor



April 21, 1953 T. O. SUMMERS, JR

GYRO-CONTROLLED SERVOMOTOR 4 Sheets-Sheet l Filed Oct. 13, 1947 R I ATTORNE).

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GYRO-CONTROLLED SERVOMOTOR Filed Oct. 13, 1947 4 Sheets-Sheet 2ATTOQ/VE'X A ril 21, 1953 1-. o. SUMMERS, JR 2,635,836

GYRO-CONTROLLED SERVOMOTOR Filed Oct. 15, 1947 4 Sheets-Sheet :5

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GYRO-CONTROLLED- SERVOMOTOR Filed Oct. 13, 1947 4 Sheets-Sheet 4#wewron. 7homaa 0. Jam/new, r.

K ATTORNEY.

Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE GYRO-CONTROLLEDSERVOMOTOR Thomas Osmond Summers, In, Los Angeles, Calif.

Application October 13, 1947, Serial No. 779,626

34 Claims.

This invention relates to machine elements and mechanisms, and moreparticularly to gyroscopes.

An object of my present invention is to provide a servomotor capable ofdelivering energy to a mechanism in a manner causing that mechanism toperform useful Work, and, in cooperative association therewith, agyroscopic control which not only regulates the servomotor, i. e.,determines when and to what extent the mechanism served by theservomotor shall operate, but which also serves as a source of theenergy required by that mechanism in performing its useful work.

Another object of the present invention is to provide a control surfaceactuator servo to retard or damp angular movements of the aircraft onwhich it is mounted by exerting a force against the surface it controlsproportional to the rate of angular movement of the aircraft, whichforce is opposed by the aerodynamic spring resistance developed againstthe surface as a result of forward speed. Further, the present inventionseeks to provide a damper servo for aircraft, capable of applyingdamping moments thereon which are independent of air speed and altitude.

A more detailed object of this invention is to provide an automaticnavigational instrument capable of guiding a moving craft substantiallyso as to maintain a predetermined path through space, Which instrumentwhile not being limited in its applicability to the field of aviation,is particularly adapted for use in connection with modern, ultra highspeed airborne craft and missiles because of its extreme sensitivity andsubstantially immediate response to any deviation from prescribed courseexperienced by the craft upon which the instrument is borne, and alsobecause of the large quantity of instantly available kinetic energy, inproportion to its size and weight, which the instrument is capable ofsupplying to a working mechanism.

In still further detail, the presen invention seeks to provide a controlsystem for high speed aircraft which achieves stabilisation through theexpedient of a gyroscope so mounted upon the craft that it is sensitiveto angular movement of the craft, and which is capable of limiting anysuch angular movement by means of a control surface movable by kineticenergy derived from the rotor of the same gyroscope, thus avoiding thenecessityof providing a separate flywheel or other independent source ofkinetic energy for the performance of desired work.

A still further object of my invention is an auxiliary control featurewhereby an instrumentality apart from and operable independent of 2 thegyroscopic control can be employed to apply force derived from the gyrorotor to the crafts control mechanism.

Yet another object, is to provide a gyroscopic control achievingstabilization of the general character indicated wherein a variablepower output transmission means, for example a multiple disc slipfriction clutching mechanism is employed for releasably inter-engaging asource of energy and a power output and wherein this mechanism isactuated by direct mechanical interconnection between the rotor-bearingcasing and the clutch mechanism whereby precession of the rotor-bearingcasing is limited by the clutch mechanism. In this connection, it mightbe explained at this point that importance attaches to this detail ofthe invention for the reason that although the gyroscope is fullysensitive to angular movement about a certain axis, it precludesprecession of the gyroscope far enough to make it sensitive to angularmovements about other axes. Illustrative of this is the fact that astabilizing instrument constructed and mounted upon a craft inaccordance with the principles of the present invention might be capableof stabilizing the craft against pitching only, and by limiting thegyroscopic element of the apparatus so that it cannot process more thana predetermined minimum, the instrument is prevented from becomingappreciably sensitive to yawing and rolling of the craft.

Yet another object of the invention is to provide a combined mechanismfor performing useful work and for controlling and regulating the workperformed thereby to the extent of determining when and to what extentenergy shall be supplied to the mechanisms output device, as hereinaboveindicated, which mechanism is of remarkably small size and light weightand is characterized by extreme sensitivity and substantially immediateresponsiveness and, accordingly, is particularly adapted for use inconnection with relatively small high speed aircraft, and which,nevertheless, is highly dependable and sufficiently rugged to withstandthe severe condition of operations apt to be encountered.

For the purposes of the present disclosure, the terms craft and aircraftare interpreted as including all types of missiles and land vehicles, inaddition to the ordinary connotations associated with the words.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth in the followingdescription of the preferred forms of my invention which are illustratedin the drawings accompanying and forming part of the specification. Itis to be understood that I do not limit myself to the showing made bythe said drawings and description, as I may adopt variations of thepreferred forms within the scope of my invention as set forth in theclaims.

Referring to the drawings:

Figure 1 i a view taken in longitudinal section through the housing of aservomotor' incorporating the principles of the present invention, andshowing the mechanism thereinside in side elevation.

Figure 2 is a longitudinal medial section taken through the mechanism,as well. as thehousing',

of Figure 1.

Figure 3 is a sectional view taken upon the" line 3-3 of Figure 1, withthe direction, of. view as indicated.

.Figure 4 is an irregular sectional view taken upon the line 4-4 ofFigure 1, with'the direction of view as indicated.

Figure 5 is a compound sectional view, the planes of section beingindicated by the lines 55 of Figure l', and the direction of view by thearrows.

Figure 6 is a diagram illustrative of theelectric circuits andconnections associated with the servomotor.

Figure '7' is a view similar toFigure 3 showing a modified form ofconstruction.

Figure 8' is a diagrammatic view illustrative of a manner in which theservomotor of the present invention is mounted upon the craft which. itis. to stabilize, and the manner connecting the servomotor to the craftscontrol mechanism.

Specifically describing that embodiment of my invention which has beenchosen for illustration and description herein, my improved servomotoris enclosed within a. housing indicated in its. entirety at I I, andcomprises preferably a base portionI'Z and a topportion I3 removablysecured thereto as a plurality of'cap screws. I 4' (see Figures 3 and8). Mounted within the cap portion t3 and for rotary movement about anaxis extending longitudinally thereof is the rotor-bearing oasingv I6 ofagyroscope indicated in its entirety at I1. Preferably the mounting forthe casing I6 comprises a pair of opposed axially aligned trunnions I8threaded through opposite end walls of the housings top portion. I3 andremovably anchored in selected position of axial adjustment as by locknuts I9 threadedupon parts of the trunnions I8 projecting outwardly fromthe housing. Antifriction bearings 2| support the ends of therotor-bearing casing I 6 upon the inner ends of the trunnions I8.

The rotor 26 of the gyroscope I1 is supported at. one end by a shaft 21,the axis of which intersects the axis of rotary movement of therotorbearing casing It; and this shaft 21 is journalled by means ofananti-friction bearing 2%. Rigid with the shaft 27 is a cylindrical shell3| preferably composed of suitable material having a relatively highspecific gravity, an ideal material for such purposes being sinteredtungsten.

Inasmuch as the modificationpresently being described is to beelectrically driven, the winding 32 of a permanent magnet, D. C. motor,is fitted within the shell 3|. This winding 32 serves as the armatureoperating within the field of a permanentmagnet 33' which surrounds theshaft 21: but remains stationary While the shaft revolves since it issupported by a stationary shaft 34 disposed in co-axial alignment withthe rotor shaft 21. This stationary shaft 34 also supports a secondanti-friction bearing 36 upon which the other end of the gyro rotor 26is supported.

A spur gear II is provided at the outer end of the shaft 21 which, asexplained hereinabove, is rigid with the rotor 26 and consequentlypartakes of its rotation. Emmeshed with the spur gear AI is a relativelylarge gear 42, the shaft 43 of which is suitably mounted inanti-friction bearings 44 carried by an extension: 46 of therotorbearing casing I6. The shaft 43 also is provided with a relativelysmall spur gear 431 which emmeshes a large driven gear 48, also carriedby a shaft 49 revolubly supported by anti-friction bearings-5i and 52.,respectively; one of which is carried by the extension 45 and the otheris carrie'd'by' a web 53 which also constitutes a portion of therotor-bearing casing. This shaft 49 is parallel to the shaft 21 of therotor 26. A socket 5 5 is provided on the inner end .of the shaft '49and the parts are so proportioned and arranged'that this socket 54' isspaced only slightly to one side of the axis of rotary movement of therotor-bearing casing, i. e., the axis of the trunnions I8.

Disposed substantially in alignment with the shaft 49 but on theopposite side of the axis of the trunnions I8 is another shaft 6| whichis revolubly mounted within anti-frictionbearings 62 carried by apedestal 63 rigid withthe top portion I3 of the housing II.Consequently, the shaft 6| does not partake of the movements of therotor beari'ng casing 26, and since the shaft 6| is to be driven by theshaft 49, a universal coupling 64 is employed to interconnecttheseshafts as and 33.

Thus it may be seen that the shaft 53 and a driving gear 65 which isrigid with its outer end arerotated continuously by energy derived fromthe kinetic energy of the rotor 26 of the gyro I-I regardless of theposition which the rotorbearing casing I6 may occupy with respect to itsrotational movement about the axis of the trunnions I8.

Within the base portion I2 of the housing II, a clutch shaft II isrevolubly mounted in aligned anti-friction bearings I2 and I3 mountedrespectively in an end wall Id of the base portion I2 and in a pedestalI6 upstanding from the bottom wall II of the base portion I2. In orderto achieve axial adjustment of the shaft II, the bearing 72 is carriedby a stud I8 threaded through the end wall I4 and provided with a locknut I9 accessible exteriorly of the housing The inner end of the clutchshaft 'I'I carries a bevel bear BI enmeshed with a sector gear 82 whichin turn is carried by a shaft 83 extending perpendicularly with respectto the shaft II and journalledwith anti-friction bearings 84 and 86. Thebearing 84 is carried by a web 8'! extending inwardly from the oppositeend wall 88 of the housings base portion, whereas the bearing 86 ismounted within a side wall 89 through which the shaft 83 extends. A looknut 9| releasably retains the bearing $6 in position and preferably afluid-tight seal is established between the shaft 83 and the housing IIas by means of an O ring gasket 92 seated Within an annular groove 93 in2- the hub 9d of an arm or lever 96 which is rigidly secured to theouter end of the shaft 83, the gasket 92 being in frictional engagementwith Variable power output transmission means are provided forreleasably connecting the shaft H to the driving gear 65 to be rotatedthereby optionally in either direction. This variable power outputtransmission connecting means preferably takes the form of a multipledisk clutch, indicated in its entirety at I M. It will be appreciatedthat any suitable means which will transmit energy from the casing 26 tothe power output of the servo mechanism in an amount varying inproportion to the precessional force of the casing may be utilized inplace of the multiple disk friction slip clutch IOI. This clutchcomprises a pair of bevelled driven gears I02 and I03, and since both ofthese gears I02 and I03 are enmeshed with the driving gear 60, thelatter also is bevelled. Being enmeshed with the driving gear 56 onopposite sides of its axis of rotation, the two gears I02 and I03 arecontinuously rotated thereby in opposite directions. Each of the twogears 502, I03 is provided on its inner face with a friction lining IIIand H2, respectively. A collar I I3 is splined to the shaft II for axialsliding movement with respect thereto and for rotary movement therewith,and opposite faces of the collar I I3 are provided with friction liningsH5 and I ll. Preferably a plurality of clutch disks II8 are interposedbetween the friction lining III on the gear I02 and the friction liningII6 on the collar; and similarly a plurality of clutch disks II9 areinterposed between the friction lining II I and the friction lining II2on the gear I03.

' Thus it may be seen that by sliding the collar II3 upwardly, as viewedupon Figure 2, i. e., toward the gear I03, the collar will befrictionally connected to the gear I03 and thereby effect rotation ofthe shaft 'II in that direction in which the gear I03 is rotated by thedriving gear 66. Similarly, when the collar II3 is moving downwards,.asviewed upon Figure 2, i. e., toward the of gear I02, the shaft II willbe connected through the clutching mechanism to the spur gear 66 androtated thereby in the opposite direction Since the shaft II isconnected to the output lever 90, it will be apparent that movement ofthe collar II3 in one direction causes the lever 96 to move in onedirection of its movement, whereas reverse movement of the clutch collarI I3 causes opposite movement of the output lever 96.

Means are provided for actuating the clutch by precessional movement ofthe rotor-bearing casing I 3, i. e., by rotary movement of the casing I6about the axis of the studs I5. Rigidly affixed to the extension 40 ofthe rotor-bearing casing I 5 is an arcuate plate I26, the center ofcurvature of this plate I25 lying within or closely adjacent the axis ofprecessional movement of the casing IS. A slot I2! is formed in theplate I20, this slot extending obliquely with respect to the directionof annular movement of the plate I25 transversed by the plate when thecasing swings on its axis, as is best shown in Figure 2.

A rock shaft I3I (see Figure 3) extending transversely across thehousing I I between the two spaced driven gears I02 and I03 is pivotallymounted in opposed and axially aligned bearings I32 preferably in theform of studs I33 threaded through the opposed side walls of thehousings base portion I2, each of the studs. being preferably providedwith a lock nut I34. A lever I38 rigid and preferably integral with theshaft I3I extends radially therefrom beyond the base portion I2 and intothe cap portion I3 so that an anti-friction bearing I31 carried by theouter end of the lever I 36 can be received within the inclined arcuateslot I21. The shaft I3I is also provided with preferably a pair ofopposed clutchactuating arms I38 extending radially therefrom topositions preferably on diametrically opposite sides of the clutch shaftII where each of the arms I38 is provided with an upwardly extending pinI39, on the inner end of which an anti-friction bearing MI is mounted.These anti-friction bearings MI fit nicely within an annular groove I42in the outer peripheral surface of the clutch collar II3, as mostclearly shown upon Figure 4.

Figure 8 illustrates the manner in which the presently describedmodification of my gy o servomotor should be mounted upon an aircraft inorder to effect stabilization thereof about a particular axis. Consider,for example, that the air foil IEI of Figure 8 functions as the rudderon an airplane and hence is capable of exerting influence over theaircraft with respect to rotary movement thereof about a vertical axis,such movements commonly being known as yawing. The gyro servomotor ofFigure 8, therefore, should be mounted upon the ship so that itsgyroscope I1 is sensitive to yawing movements of the craft, with theresult that the shaft 21 of the rotor should lie in a horizontal plane,as should also the axis of precessional movement of the rotor-bearingcasing I6.

Because of the relative positioning of the various elements of themodification of my invention presently being described, this prescribedposition of the gyro servomotor will cause the axis of the output shaft83 to extend vertically and the output lever 96 to be mounted forreciprocatory rotary movement in a horizontal plane. It is easilyarranged, therefore, to connect the air foil I5I to the lever 93 to beoperated thereby by means of a simple link mechanism illustrated more orless diagrammatically at I52, one end of which is pivotally connected tothe outer end of the lever 96 and the other end of which is con nectedto a lever I53 rigid with the air foil I 5| and extending laterallytherefrom in a horizontal direction, i. e., in a direction perpendicularto the axis about which the air foil I5I is capable of moving.

Because of the fact that the spin axis of the gyro lies in a horizontalplane, any yawing action of the craft by which it is borne willimmediately cause the gyroscope to precess, such precession being mademanifest by turning movement of the rotor-bearing casing about the axisof the trunnions IS, in accordance with the wellknown principles ofgyroscopic action.

Because of the fact that the minimum possible clearance between thevarious friction elements of the clutch exists, coupled with the factthat all of the machine parts interposed between the rotor-bearingcasing and the clutch parts, the actual angular distance through whichthe rotorbearing casing turns before any further precession is limitedmay well be extremely small. In any event, the precessional movement ofthe rotor-bearing casing will be in that direction about the axis of itspivotal support which is illustrated by the direction in which the gyrosrotor is spinning and by the direction in which the yawing movement ofthe craft occurs. If the direction of precessional movement of therotor-bearing casing is that which makes the slot I2! in Figure 1 moveto the left, as considered in that figure, the clutch-actuating leverI36 will be swung in counter-clockwiserotation about the 7 axis .cfftheshaft 131 and the clutch enga i anti-frictionhearing] wlllbe movedupwards, as ,vietvednn Figure 1; thereby frictionally interconnectingthe-clutch collar 1| 13 with the driven gear 193 and causing the shaft11 to rotate inthe samedirection. .Onthe other hand, if theprecess'mnalmovement of the rotor-bearing casing isin the opposite direction,:thecollarl. I3 will be frictionally interconnected with .the oppositedriven gearfiiZ, thuscausing the shaft 1.! to be rotated intheoppcsitedirection. Because of theconnection oftthe driving, or pinion, bevelgear 55 through the speed reduction gears 41, 42,4 3, anddiiiandathroughlthe flexible coupling of which the element .54 is aportion, the gear 66 is continuously' rotated ata rate muclrless thanthat of the gyro rotor which because of its relatively large massandhig-h rate of rotation, serves as a.convenient source of'kineticenergy which'may be drawn upon momentarily when occasion demands to keepthe gear tfi rotating at no great loss in speed of the gyro rotor 25even though called upon toperform useful-work requiring a relative.- lygreat amount of energy. The output of the clutch will be a function ofthe precessional force of the rotor-bearing casing as applied to theclutch collar H3 since it is wellknown that the outputof a: disk typefriction clutch is a function of the force with which the clutch disksare pressed. together. Whenthe clutch mechanism is engaged, thesector'gear 82 with the output shaft 83 and the output lever 96 will berotated with sufficient force to actuate the air foil I5! in thatdirection which will tend to retard the yawing action of the craftresponsible for the precessional movement which has caused engagement ofthe clutch. Since this precessional movement is the result ofprecessional force proportional to the rate of the yawing of the craft,the output lever 95 will develop an output force also proportional totheyaw rate. This output force from the servo which is exerted by lever 95against the air foil i5! is matched by the aerodynamic spring resistanceopposing movement of the air foil I51, which resistance is a function ofair speed and altitude. Since the aerodynamic effectiveness of thecontrol surface in producing a moment about the airframe is proportionalto the same function of air speed and altitude as the aerodynamicspring, the applied control servo force efiects a moment upon theairframe which is independent of air speed and altitude. Thus it may beseen that the servo effects a force about the yaw axis of the craftwhich is proportional to yaw rate'only and which force is independent ofair speed and altitude. In other words, the servo exerts force outputsagainst the surface it controls, which forces are proportional to therate of angular movement oft-he aircraft about the input axis of therate-sensitive gyro, as a result of which the control surface is movedagainst an aerodynamic spring, causing the surface to be deflectedthrough a large angle at low air speed, and through a comparativelysmall angle at high air speed. The damper'servo of the presentinvention, when mounted in an aircraft, provides automatic rate controlof the craft, or, in other words, proportional resisting forces on thepart of the craft through its control surfaces to angular movementsabout the input axis of the damper servo.

Such an'automatic rate control system, providing force outputs"proportional to the rate of angular-movement of the aircraft, hasconsiderable application in the field-of-missiles andhighspeed-aircraft, where -rate-gyros-havin a. high natural frequency areessential. The'naturalfre, quency of the gyroservo in the'presentinvention is determined by the aerodynamic spring of the air foil, andthetotal mass driven by the friction clutch of the servo,including themass of the control surface. Thus it maybe seen that-unlike conventionalautomatic rate control systems, the mass'of the heavy gyro rotor doesnot enter directly into the determination of the naturalfre quencyof thesystem. Rather, the aerodynamic spring and all driven mass-following thefriction clutch, includingthe mass of the linkages and the mass of theair foil, determine the natural frequency of the automatic rate controlsystem oft-he present invention. The advantage ofsuch a servo systemisrealized when the aerodynamic spring-resistance of the air foil ismadehigh. By' making the output lever t long, the'aerodynam-icspringresistance will be high, with the result that the spring masscombination of the present control system will have a high naturalfrequency.

Since it is inevitable that the rate-sensitive servo of the presentinvention will have. some time lag, as isthe. case-with any servomechanism, the servo will cause the aircraft or missile which it ratestabilizes to oscillate at some amplitude, the extent of which is afunction of the time lag of the servo. Usually, by reducing the outputof the rate servo,the amplitudeof this oscillation can be minimized.Inasmuch as aslowing down of the. gyro rotor results when the servomoves the surface it controls, theservo-outputis automatically reducedwith the slowing down ofthe gyro rotor. Thus, it is apparent that shouldthe servo cause themissile to oscillate because of inevitable timelag,the amplitude of the oscillations will'diminish, with theresult thata more stable condition will exist.

It becomes evident, therefore, that the gyro servomotor of the presentinvention will operate efficiently and with anextremely small time lagto stabilize the craft on which it is mounted when any yawing occurs. Itshould be made clear, howeventhat such stabilization does not involvemaintaining the craft upon the prescribed course. It merely will retarddeviation from a certain course, but is not capable of correcting deviation from a given course, i. e., is not capable of returning the craftto that course. Accordingly, in order to provide forsuch type of controlover the craft, it is desirable, at least in some 111- stances, toprovide an auxiliary, exteriorly operated means for engaging the clutchindependent of the gyro-operated clutch engaging means. In themodification presently being described, this auxiliary control takes theform of an electric clutching member associated with each of the drivengears Hi2 and J03, and indicated respectively at 16! and I62. In themodification/here shown for illustration, each of these clutchingmembers it] and 162 comprises an electro-magnetic coil I63 encirclingthe clutch shaft 1| preferably adjacent the outer face of the associatedgear 192 or H33, respectively. When an electric current is passedthrough the coil I63 of either of the electric clutching mechanisms It!or H52, the coil sets up a magnetic field which attracts the associatedarmature which is, in the modificationhere being described, supplied bya portion of the associated driven gear IE2 or I03, as the case mightbe. Hence, when so energized, either of the windings sets, up africtional drag which tends to rotate he d k 16.5 Qr'lfi'l, as thecase-mi h be, u n which. the ne z d l 0 magnet is mounted because of itsfrictional enagement with the associated driven gear I02 or I03developed when the two elements are attracted as the result of theaction of the electromagnet. Each of the disks I66, I61 is journalled asby an anti-friction bearing I60 which freely rotates upon the shaft 1|,with the result that when the electro-magnet of one of the electricalclutch mechanisms is energized, the associated disk rotates freely uponthe shaft 1 I, the direction of rotation depending upon which of the twoelectro-magnets has been energized.

Each disk I66, I61 is provided with a pin I1I, I12 extending outwardstherefrom, each of these pins being offset from the axis of the disk,with the result that before a disk makes a complete revolution, the pinI1I or I12 will engage a finger I13, I14, respectively, each of which isrigid with and projects laterally from a portion of the rotorbearingcasing I6. Thus it may be seen that the effect of supplying electricalenergy to either of the electro nagnets I63 is to rotate the associateddisk I66 or I61, and through engagement of its associated pin I1! orI12, impart rotary movement to the rotor-bearing casing I6 about theaxis of the trunnions I8 and thereby cause the arcuate plate I26 to movein such a manner that the clutch-actuating arm I36 is swung about theaxis of its pivotal support. This effects engagement of the clutch inthe same manner as when engaged by precession of the gyroscope.

In order to energize each of the electro-magnets I63, a pair ofresilient brushes I16 (see Figure are mounted upon and electricallyinsulated from the housing I I, preferably by being secured to thesealing gasket I11 which preferably is interposed between the twosections I2 and I3 of the housing I I so as to aid in making itwatertight. Each of the rings I66, I61 is also provided with a pair ofarcuate contacts I18, each i;

of which is engaged by one of the brushes I16, and these two contactsI18 of each electro-magnet are electrically connected by conductors (notshown) to the two terminals of the associated electro-magnet I 63. As isindicated in the wiring diagram of Figure 6, one of the brushes I 16 ofeach of the electro-magnets I63 is connected as by a conductor I19through preferably a conventional connector I80 mounted as by screws I8Ion one of the walls of the housing (see Figure 4). The terminal of theconnector I80 to which the two brushes I16 of the two electro-magnets isadapted to be connected as by a conductor I82 to one of the terminals ofthe source of electrical energy, such as a battery I84. The otherterminal I86 of the battery I94 is connected as by a conductor I81 tothe movable blade I88 of a double-throw switch I89 which optionally maybe brought into engagement with either of two contacts I9I, I92, each ofwhich is connected as by a conductor I93, I94 leading through the sameconnector I80 to the brush I16 of one of the electro-magnets I63, whichbrush is connected to the opposite terminal of the associatedelectro-magnet from that to which the conductor I19 is connected.

Here it should be explained that the doublethrow switch I89 has beenused merely in an exemplary sense inasmuch as it is intended here toindicate that current can be supplied from the source of electricalenergy optionally to either of the electro-magnets I63. Such control canbe exercised either manually or automatically, in which event thepick-off mechanism and gyroscope control apparatus disclosed in PatentNo. 2,423,270, issued to me on July 1, 1947, would be entirelysatisfactory. Furthermore, the functions performed by the switch I89 canalso be performed by radio signal whereby remote control can beexercised over the craft upon which the gyro servomotor of the presentinvention is operatively mounted.

Preferably the same source I84 of electrical energy is employed toenergize the winding 32 of the gyro rotor 26, and the same connector Ialso serves to connect the source I84 to the winding of the rotor 26, asis clearly indicated in Figure 6.

Figure '7 illustrates a modified form of construction wherein a motor20I separate and independent of the gyroscope is used as the means forrotating the two driven gears of the clutching mechanism. Preferably themotor 20I is mounted on the outside of the gyro rotor housing I I as bya plurality of screws 202, the motors shaft 203 extending through thehousing so that a bevel pinion gear 66' carried by the inner end of theshaft 203 enmeshes both driven gears I02 and I03. The clutchingmechanism in this modification may be identical with that of thepreviously described modification and be actuated by a pair of identicalanti-friction bearings I4I carried by the arms I38 of a rock shaft I3I'from which a lever I36 extends into position for an anti-frictionbearing I31 mounted upon its outer end to seat within an inclined slotI21 in an arcuate plate I26 which is carried by an extension 46' of therotor-bearing casing. Accordingly, in this modification of my invention,the clutching mechanism is engaged and disengaged so as to drive theclutch shaft 1|, and with it the associated output shaft and lever (notshown) optionally in either direction as the result of rotationalmovement of the rotor-bearing casing about the axis of its precessionalmovement either by gyroscopic action or by separate control, as in thecase of the first described modification. However, the energy foroperation of the output shaft after the clutch has been engaged isderived from a source other than the rotor of the gyroscope. This, ofcourse, eliminates the necessity of employing the chain of reductiongears and the flexible driving connection and thereby materiallysimplifies the interior construction of the gyro-controlled servomotor.Consequently, in installations where the additional weight of theauxiliary motor 20I is not an important factor, this last describedmodification may be preferred.

I claim:

1. As a novel combination, a movable craft, means operably mountedthereon for controlling movement thereof, a gyroscope comprising acasing and a rotor journalled therein, means mounting said casing onsaid craft for freedom of movement about a predetermined axis of saidcraft perpendicular to said rotors axis of rotation whereby saidgyroscope is caused to precess about said predetermined axis when saidcraft develops rotational movement about an axis perpendicular to saidpredetermined axis, means for selectively connecting said rotor to saidmovementcontrolling means to transmit the kinetic energy of said rotorthereto, and means operable by said precessional movement of saidgyroscope to actuate said connecting means to drive saidmovement-controlling means by said rotor.

2. As a novel combination, a movable craft, means operably mountedthereon for controlling movement thereof, a gyroscope comprising acasing and a rotor journalled therein, means mounting said casing onsaid craft for freedom of movement about a predetermined axis of saidcraft perpendicular to said rotors axis of rotation whereby saidgyroscope is caused to'precess about said predetermined axis when saidcraft develops rotational movement about an axis perpendicular to saidpredetermined axis, means for actuating said crafts movement-controllingmeans, and means actuated by preces'sional movement of said gyroscopefor Connecting said-actuatingmeans to said rotor to be operated thereby.

3'. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted upon said housing and having a single axisof rotation, a gyro rotor journaled on said "casing for rotationabout anaxis perpendicular t'o'said single axis, 'saidrotor-bearing casing beingprecessed about said single axis by movements of said housing about anaxis perpendicular to said single axis, a control actuator movablymounted 'oh said housing, and means act'uatedby said precessionalmovement of said rotor bearing casing for optionally connecting saidcontrol actuator 'tosaid rotor to be moved thereby or disconnecting saidcontrol actuator from said rotor.

4. A gyro operated and controlled servomotor co rnprising a housing, agyro casing mounted upon said housing and having a single axis ofrotation, a gyro rotor journaled on said casing r r rotation about anaxis perpendicular to said 's' jgl'e axis, said gyro casing beingpreces'sed in either direction about said single axis by movements ofsaid housing about an axis perpendicular to said single axis, means forspinning saidrotor, a control actuator mounted for re- -ciprocatorymovement with respect to said housing, means optionally e'ngageable withor disengage'able from said rotor for moving said conan actuator in onedirection of its reciprocatory movement, means optionally engageablewith or disengageable from said rotor for moving said control actuatorin the other direction of its reciproca tory movement, and meansoperated by said casing when processing in one direction aboutsaidsi'ngle axis for disengaging a predeterrniiied one of saidactuator-moving means and engaging the other of said actuator-movingmeans and when -'precess1ng in theother direction about said single axisfor disengaging said other of said actuator-moving means and engagingsaid predetermined one of said control-moving means.

"5. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of 'precessionalmovement in either direction about an axis'of said housing, a gyro rotorrevolubly mounted therein, means for spinning said rotor, a driving gearbperably connected to said rotor to be rotated thereby, a pair ofopposed driven gears journalled in said housing and enmeshed with saiddriving gear tobe rotated in opposite directions thereby, a drivingclutch plate rotated by each of said gears, a driven clutch platerevolubly mounted within said housing and movable optionally intoengagement with either of said driving clutch plates, and means'operableby s'aid'casing when 'precessing'in one dire'ctionfo'r moving saiddriven clutch plate into engagement with a predeter- "i'nihedone of saiddrivingclutch'plates and operable by said casing when precessin'g in theopposite direction for moving said driven clutch "plate into engagementwith the other of said difivin'g clutch "plates.

6. 'A gyro operated and controlled servomotor "comprising a housing, arotor-bearing casing mounted for freedom of precessio'nal movement aboutan axis of said housing, a gyro rotorrevolubly mounted therein, meansfor spinning said rotor, a driving gear operably connected to said rotorto be rotated thereby, a working shaft journalled within said housing,and clutch meansfor releasably connecting said working shaft to saiddriving gear to be rotated thereby and comprising a driving clutch platerevolubly mounted on said working shaft, a driven gear carried by saidclutch plate, and enmeshed with said 'driv'ing gear, a collar splined tosaid Working shaftfor rotation therewith and axial sliding movement withrespect thereto, driven clutch means on a face of said collarand'engageable with said driving clutch disk when said collar is movedaxially theretoward, and means actuated by said casing when precessingfor moving said collar axially.

7. A gyro operated and controlled servo'motor comprising a housing, arotor-bearing casing mounted for freedom of precessional movement ineither direction about an axis of said housing, a gyro rotor revolublymounted therein, means for spinning said rotor, a drivin gear operablyconnected to said rotor to be rotated thereby, a

working shaft journalled within said housing'and clutch means forreleasably connecting said working shaft to said driving gear to berotated' thereby optionally in either direction and comprising a pair ofopposed driving clutch plates revolubly mounted on said working shaft inspaced apart relation to each other, a driven gear carried by each ofsaid clutch plates and enmeshed withs'aid driving gear on opposite sidesthereof whereby said driven gears are rotated thereby in oppositedirections, a collar splined to said working shaft for rotationtherewith and axial sliding movement with respect thereto, driven clutchmeans on opposite faces of said collar and engageable selectively witheither of said dri ing clutch disks when said collar is moved axiallytheretow'ard', and means actuated by saidcasing when precessing in onedirection for moving said collar axially in one direction and whenprecessing in the opposite direction for moving said collar in theopposite axial direction.

8. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of precessio'nalmovement about an axis thereof, a gyro rotor revolubly mounted withinsaid casing, an output shaft mounted within said housing for rotationalmovement about an axis of said housing apart from said rotor-bearingcasing, reversing mechanism including a driving gear operativel'yassociated with said output shaft for optionally turning said shaft ineither direction when said drivmg gear is rotated, and flexible drivemeans conmeet ng said driving gear to said rotor to be drivencontinuously thereby in all positions of precessional movement of saidrotor-bearing casing about said axis of precessional movement thereof.

9, A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of precessionalmovement about an axis thereof, a gyro rotor revolubly mounted withinsaid casing, an output shaft mounted within said housing forrotationalmovement about an axis of said housing apart from said rotor-bearingcasing, a'pair of opposed driven gears journalled on said output shaftclutch means interposed between each of said driven gears andsaid'output shaft whereby said output shaft can be rotated optionally'byeither of said gears, a driving geanjournalle'd within said housing,said driven'gears being enmeshed with said driving gear on oppositesides of the axis of rotation thereof whereby said driven gears arerotated in opposite directions by said driving gear, and flexible drivemeans connecting said driving gear to said rotor to be rotatedcontinuously thereby in all positions of said casing about said axis ofprecessional movement thereof.

10. In combination, a rate gyroscope comprising a. casing mounted forprecessional movement, a source of kinetic energy, a movable poweroutput, means including a variable output friction clutch for releasablyconnecting said power output to said energy source to be driven thereby,and means operated by said casing during precessional movement thereoffor obtaining an output from said clutch proportional to theprecessional force of said casing.

11. In combination, a rate gyroscope comprising a casing mounted forprecessional movement, a source of kinetic energy, a movable poweroutput, means including a reversing mechanism and a variable outputclutch mechanism for releasably connecting said power output to saidenergy source to be driven thereby, and means operated by said casingduring precessional movement thereof in one direction for actuating saidclutch mechanism to obtain a clutch output proportional to precessionalforce for movement of said power output in one direction of itsmovement, said clutch-actuating means being operated by said casingduring opposite precessional movement thereof for actuating said clutchmechanism to obtain a clutch output proportional to precessional forcefor movement of said power output in the other direction of itsmovement.

12. In combination, a rate gyroscope comprising a casing mounted forprecessional movement, a source of kinetic energy, a movable poweroutput, means including a reversing mechanism and a variable outputclutch mechanism for releasably connecting said power output to saidenergy source to be driven thereby, means operated by said casing duringprecessional movement thereof in one direction for actuating said clutchmechanism to obtain a clutch output proportional to precessional forcefor movement of said power output in one direction of its movement, saidclutch-actuating means bein operated by said casing during oppositeprecessional movement thereof for actuating said clutch mechanism toobtain a clutch output proportional to precessional force for movementof said power output in the other direction of its movement, said clutchmechanism including means for substantially limiting precessionalmovement of said casing.

13. In a control device for movable craft, a rate gyro including acasing mounted upon said craft for rotation about a single axis, a gyrorotor journaled within said casing for rotation about an axisperpendicular to said single axis, said gyro being precessed about saidsingle axis by angular movements of said craft about an axisperpendicular to both the single axis and the rotor axis, means mountedupon said craft for controlling the angular movement thereof, means forrotating said gyro rotor, means continuously driven by said rotor, andmeans operable upon said preoession of said gyro to connect saidcontinuously driven means to said movement controllin means in order tocontrol the angular movement of said craft.

14. In a control device for movable craft, a rate gyro including acasing mounted upon said craft for rotation about a single axis, a gyrorotor journaled within said casing for rotation about an axisperpendicular to said single axis, said gyro being precessed about saidsingle axis by angular movement of said craft in the gyro-sensitiveplane, means mounted upon said craft for controlling the movementthereof, means fo rotating said gyro rotor, a clutchin means driven bysaid rotor and interposed between said rotor and saidmovement-controlling means, and clutch engaging means directly connectedto said casing for actuating said clutching means upon precessionalmovement of said casing to drive said movementcontrolling means by saidrotor.

15. In combination, a rate gyroscope comprising a casing mounted on asingle axis for precessional movement and a rotor revoluble within saidcasing on an axis perpendicular to said single axis, means for rotatingsaid rotor, mechanism external to said gyroscope, means interposedbetween said rotor and said mechanism and having a driving member and adriven member, said drivin member being continuously connected to saidrotor and said driven member being continuously connected to saidmechanism, and means operable by the precessional movement of said gyroto connect said driving member to said driven member so that the kineticenergy of said rotor can be utilized to operate said mechanism.

16, In combination, a rate gyro including a casing mounted on a singleaxis for precessional movement thereabout, a gyro rotor mounted on saidcasing with its axis perpendicular to said casing axis, a source ofenergy, a movable power output, a clutch mechanism comprised of adriving member and a driven member, means for continuously connectingsaid driving member to said energy source, means for continuouslyconnecting said driven member to said power output, means for applying atying force between said driving member and said driven memberproportional to the precessional force exerted by said casing so thatthe output of said clutch will vary directly with precessional force.

1'7. The combination set forth in claim 16 wherein the said gyro rotoris the said energy source.

18. The combination set forth in claim 16 including means independent ofthe precessional force of said casing for applying a tying force betweensaid driving member and said driven member.

19. In combination, a rate gyro including a casing mounted on a singleaxi for precessional movement thereabout, a gyro rotor mounted on saidcasing with its axis perpendicular to said casing axis, a source ofenergy, a movable power output, a clutch mechanism having first andsecand members, means for varying the contact pressure between saidmembers, means for connecting one of said members to said energy source,means for connecting the other of said members to said power output andmeans for transmitting the precessional force of said casing to saidpressure varying means so that said clutching mechanism develops anoutput proportional to precessional force.

20. The combination set forth in claim 19 wherein the said gyro rotor isthe said energy source.

21. The combination set forth in claim 19 including means independent ofthe precessional force of said casing for applying a force to saidpressure varying means,

22. As a novel combination, a movable craft, a control surfaceoperatively mounted thereon for controllingmovement thereof, a rate gyrocarried anemone 'by said craft including a casing mounted on asing-le'axi'sfor precessional movement thereabout, agyro rotor mountedon said. casing with its axis perpendicular to sa'idcasing axis, asource of energy, clutching mean for selectively connecting saidenergysource' to said control surface, means for applying a variable clutchengaging force to said clutching means tovary the outputther of inproportion to said engaging force, and means connecting said casing withsaidforce applying means for varying said clutching means output inproportion to the precessionalforce ofsaidcasing.

"23; As anovel combination, a movable craft, a -control surfacesoperatively mounted thereon for controlling movement thereof, arate gyrocarried by said craft including a casing mounted on a single axis forprecessional movement thereabout, a gyro rotor mounted on said casinivith'its ax-is perpendicular to "said casing axis, meansfor drivingsaid gyro rotor, clutching means for selectively connecting saidgyrorotor to said control surface, means for applying a variable clutchengaging'force to said clutching means to vary the output thereof inproportion to said engaging force, and means connecting said casing.with said forceapplying 'meansfor varying said clutching means output inproportion to the precessional force of said casing.

24; Asa novel combination, amoveable craft, a control'su-rface.operatively "mounted thereon for controlling movement thereof, a rategyro carried by said-craft including a casing mounted on a single-axisfor precessional movement :in op positedirectionsthereabout, a gyrorotor mountedon said casing with its axis perpendicular to said casingaxis, a source of energy, reversible clutching means for selectivelyconnecting said energy source to said control surface to move saidsurface in opposite directions, means for applying avariable clutchengaging force to said clutching means'to vary the output of saidclutching means in either direction, and means connecting said casingwith said force applying means for adjusting the said reversibleclutching means output in proportion to precessional force of saidcasingand for determining the direction of movement of said controlsurface.

25. As a novel combination, the combination set'forth in claim 24including means independent of the precessional force of said casing forapplying a clutch engaging force to-said reversible clutching means tomove said control surface in opposite directions.

26. Asa novelcombination, a moveable craft, a control surface mountedthereon for receiving an aerodynamic forceoperative to oppose angularmovement of said craft, the magnitude of said force varying directlywith the rate of angular movement, a rate gyro carried by said craftand' having 'a casing mounted on a single axis for precessional movementin opposite directions, a gyro rotor mounted on said casing With itsam's perpendicular to said casing axis, said gyro developing aprecessional force proportional to the turning rate of said craft aboutthe gyro sensitive plane, a sourc of energy, reversible clutching meansfor selectively connecting said energy source to said control surface tomove said surface inoppos'ite directions, means for applying a variableclutch engaging force to said clutching means "for varying the outputthereof in either direction, means connecting said casing and said forceapplying means for adjusting the said clutching means engaging force inproportion to precessional force of said casing and for de- '16termining the direction-of movement ofsaidnOIitrol surface,saidxreversible clutching-means applying to said control surface a forceequal and opposite to said aerodynamic force.

27. As a novel combination, the combination set forth in claim 26including means independent of. the precessional force of said casingfor applying a clutch engaging force to said reversible clutching meansto move said control surface in opposite directions.

.28. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of precessionalmovement about an axis thereof, a gyro rotor revolucly mounted Withinsaid casing for spinning about an axis perpendicular to said precessionaxis, means for spinning said rotor, a first shaft revolubly mounted onsaid casing for movement therewith and having its axis of rotationparallel to said rotor spin axis and intersecting said precession axisfor all positions of said .casing, gearing means for connecting saidrotor to said first shaft, a second shaft revolublymounted on saidhousing about an axis perpendicular to and intersecting said precessionaxis at the point where said first shaft axis intersects said precessionaxis, a universal joint locationed at said intersecting point andconnecting said first shaft to said second shaft for rotating saidsecond shaft by said first shaft, and servomotor output means driven bysaid second shaft.

29. A gyro operated and controlled servomotor as defined in claim 28including means for controlling said servomotor output by precessionalmovement of said rotor-bearing casing.

30. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of precessionalmovement in either direction about an axis of said housing, a gyro rotorrevolubly mounted in said casing, a source of energy, a driving gearoperably connected to said source to be rotated thereby, a pair ofopposed driven gears journalled in said housing and enmeshed with saiddriving gear to be rotated in opposite directions thereby, a drivingclutch plate rotated by each of said driven gears, a driven clutch platerevolubly mounted Within said housing and movable optionally intoengagement With either of saiddri-ving clutch plates, and a linkageinterposed 'between said casing and said driven clutch :plate to movesaid driven clutch plate into engage- .ment with one or the. other ofsaid driving clutch plates with a force proportional to the precessionalforce of. said casing.

3-1. A gyro operated and controlled servomotor comprising a housing, arotor-bearing casing mounted therein for freedom of precessionalmovement in either direction about an axis of said housing, a gyro rotorrevolubly mounted in said casing, a source of energy, a driving gearoperably connected to said source to be rotated thereby, a pair ofopposed driven gears journalled in said housing and enmeshed with saiddriving gear to be rotated in opposite directions thereby, a drivingclutch plate rotated by each .of said driven gears, a driven clutchplate revolublymounted Within said, housing and movable optionally intoengagement With either of said driving clutch plates, and a leverpivotally mounted on said housing and having one end connected to saidcasing and the other end connected to said driven clutch member, saidlever being moved inopposite direction by said casing upon precession ofsaid casing inopposite directions to 17 thereby move said driven clutchplate into engagement with one or the other of said driving clutchplates with a force proportional to the prccessional force of saidcasing.

32. A gyro operated and controlled servomotor comprising housing, arotor-bearing casing mounted therein for freedom of precessionalmovement in either direction about an axis of said housing, a gyro rotorrevolubly mounted in said casing, a source of energy, a driving gearoperably connected to said source to be rotated thereby, a pair ofopposed driven gears journalled in said housing and enmeshed with saiddriving gear to be rotated in opposite directions thereby, a drivingclutch plate rotated by each of said driven gears, a driven clutch platerevolubly mounted within said housing and movable optionally intoengagement with either of said driving clutch plates, a plate attachedto said casing for angular movement therewith, a slot formed in saidplate and extending obliquely with respect to the direction of angularmovement of said plate, and a lever pivotally mounted on said housingand having one end inserted in said slot and the other end connected tosaid driven clutch plate, said one end being moved in oppositedirections by said slot upon precession of said casing in oppositedirections to thereby cause engagement of said driven clutch plate withone or the other of said driving clutch plates.

33. In combination, a rate gyro including a casing mounted on a singleaxis for precessional movement thereabout, a gyro rotor mounted on saidcasing with its axis perpendicular to the axis of said casing, a sourceof energy, a moveable power output, a clutching means for connectingsaid energy source to said moveable power output, means for applying avariable-clutch engaging force to said clutching means to vary theoutput thereof, means connecting said casing and said force applyingmeans for adjusting the said clutch engaging force means in proportionto the precessional force of said casing so that the output of saidclutching means varies in accordance with the said precessional force ofsaid casing.

34. In combination, a rate gyro having a casing mounted on a single axisfor precessional movement thereabout and a gyro rotor mounted in saidcasing, a source of energy connected to said gyro rotor, a moveablepower output, variable output transmission means connecting said gyrorotor to said output proportionally to the precessional force of saidcasing, and means connecting said casing and said variable outputtransmission means for varying the energy transmitted from said energysource to said moveable power output in accordance with the precessionalforce of said casing.

THOMAS OSMOND SUMMERS, JR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,024,398 Ellsworth Apr. 23, 1912 1,422,197 Greene July 11,1922 1,904,801 Plutino Apr. 18, 1933 2,049,120 Imhof July 28, 19362,053,182 Gram et a1. Sept. 1, 1936 2,201,226 Carlson May 21, 19401FOREIGN PATENTS Number Country Date 407,737 France Jan. 7, 1910

